Continuous and discontinuous descriptions of blocked structures: The case study of Santissimo Crocifisso Church in Pretare (Italy)

Advanced numerical modelling of the masonry “Apennine Church” of Santissimo Crocifisso in Pretare, Arquata del Tronto (AP), was here utilized to have an insight into the dynamic properties and behavior of the structure under strong nonlinear dynamic excitations. The objectives were achieved by comparing nonlinear dynamic analyses through discontinuous and continuous approaches. In the discrete element approach, the Non-Smooth Contact Dynamics method, implemented in LMGC90©, was applied, adopting a full 3D detailed discretization. The Church was schematized as an arrangement of discrete rigid blocks, subjected to sliding by friction and perfect plastic collisions, governed by Signorini's impenetrability condition and dry-friction Coulomb's law, with a null restitution coefficient. In the finite element approach, the Concrete Damaged Plasticity model available in Midas FEA NX© was involved. This model allows reproducing the tensile cracking, the compressive crushing, and the degradation of the material under cyclic loads. At the end, the structure exhibited a complex dynamic behavior, because of the geometrical nonlinearity and the non-smooth nature of the contact laws. Finally, the numerical analyses provided a valuable picture of the actual behavior of the church, which is mandatory for future strengthening interventions